Refrigerating apparatus



Feb. 10, 1953 w. w. HIGHAM 2,623,916

I REFRIGERATING APPARATUS Filed March 5, 1946 3 Sheets-Sheet 1 FIG. 7

1 INVENTOR WILLIAM WH/GHAM ORNEY J Feb. 10, 1953 w w HlGHAM REFRIGERATING APPARATUS 3 Sheets-Sheet 2 Filed March 5, 1946 mmzm INVENTO-R WILLIAM WH/GHAM Y I r 'u y l: H TORNEY Feb. 10, 1953 w w, I-HGHAM 2,628,016

REFRIGERATING APPARATUS Filed March 5, 1946 3 Sheets-Sheet 3 INVENTOR F [(5, 8 WILL/AM W H/GHAM TTORNEY 3 Patented Feb. 10, 1953 mesne assignments, to Tecumseh Products Company, Tecumseh, Mich.,'a corporation of Michigan Application March 5, 1946, Serial No. 652,026

This invention relates to refrigeration and has to do particularly with a refrigerant compressor of the type commonly known as a sealed type of compressor.

Generally speaking, a, sealed type compressing mechanism is one wherein the compressor and the electrical motor for driving the same are mounted within a sealed casing or shell. 1

One of the objects of the invention is to provide a design which facilitate manufacture and assembly, affords a minimum number of parts and thereby makes it feasible to produce the compressing mechanism at a low cost.

Another object is to provide a compressing mechanism which operates substantially silently and this is accomplished in partby providing a novel spring or yieldable mountingpf the mechanism within the shell; in carrying out this object it is a further object to provide for protecting the mechanism against damage when, the assembly is not in an upright or operating position, as for example, when it is in the various positions to which it is subjected during shipment. To this end I provide resilient means for supporting the operating mechanism and for resisting.

upward, downward and lateralmovement ofthe operating mechanism and I also provide stop mean for limiting undesired movement of the operating mechanism. i

A further object is to providea simple but cating pump by which all moving tively and adequately lubricated.

A still further object is to provide. vibration dampening means for the shell or casing and for parts of the operatinginechanism. I r

A still further object is to provide for heat exchange between the refrigerant and the motor and between the refrigerant and the lubricant.

One feature is the provision of an overload thermostat to prevent excessive heating of the motor. Another feature is the provision of an oil pressure limiting tube to prevent the spraying of lubricant between the stator and ,rotor of the motor; and to aid in coolingthe lubricant.

Further objects, features, and advantages will appear from the following description, when considered in connection with the accompanying drawings wherein a preferred form of embodiment of the invention is clearly shown.

In the drawings: 4

Fig. 1 is a view in side elevation of asealed unit embodying my invention;

parts-are posi- Fig. 2 i a view in top plan of the. unit shown :inFig. 1;

4 Claims. (01. 230-58) .30 effective lubrication system including a lubri-' Fig.3 is a view in vertical section taken substantially on the line 3-3 of Fig. 2 but on a much larger scale than Fig. 2 r

Fig. 4 is a view taken substantially on line 4-4 of Fig. 1 but on a larger scale than Fig. 1 and looking into the shell from the bottom;

Fig. 5 is a view taken substantially on line 55 of Fig. 4 and showing the gas inlet;

Fig. 6 is a sectional view taken substantially on line 66 of Fig. 3 showing the pump for the lubricatingoil;

Fig. 7 is a, sectional view taken substantially on line 1-1 of Fig. 3, showing part of the lubricating system; and

Fig. 8 is a fragmentary view in elevation showing the electrical control box with a portion of the cover removed.

I have illustrated my invention 'as a sealed motor compressor unit which is indicated generally in Figures 1, 2, 3 and 4 by the letter R, the

unit being enclosed in the hermetically sealed shell or casing H. I provide operating mechanism within the hermetically sealed shell H in- "cluding a, motor. unit generally designated M, a

compressor unit generally designated C and an operating shaft generally designated S which operatively connects the motor M to the compressor unit C. The operating mechanism and the various .parts thereof will hereinafter be described more indetail.

. Referring especially to Figures 1, 2 and 3, it may be seen thatthe casing or shell H of the motor compressor unit R. comprises two portions. These portions may be fashioned from sheet metal. There is a lower portion L and an upper portion U. The lower portion L has a bottom wall I and peripheral side walls 2, and is provided with suitable supports 3 welded thereto for the external mounting of the compressor unit. The lower portion L ha a telescoping fitwith the lower edge of the substantially "cylindrical side wall 4 Of"th8 upper shell portion U and the two portionsfmay be weld united alongthe'seain, as shown at 5, for providing a hermetically sealed casing or shell. The top wall 4a .of the upper portion U of the shell is formed with a depression 6; this strengthens the top wall'of the shell, minimizes the over-all height and provides a pocket for vibration dampening material. 'For dampening vibrations a body of material 1 is placed in the depression 6 on the topof the shell. This material may be in the nature of a felted material or a substancerelatively loosely compacted so that it is capable of'absorbing and dampening vibrations and is of a non-resonant nature. This material is held snugly against the shell as by means of a plate 8 of metal, the plate being attached to the shell by a stud 9 which may be welded to the shell and which has its upper end fashioned as a head or riveted over, as illustrated. The plate 8 also covers and encloses the dampening material so as to provide a metallic surface and to prevent oil and other extraneous matter from accumulating in and about the dampening material.

I provide means for yieldingly mounting the operating mechanism including the motor M, compressor C, shaft S, and associated mechanism within the hermetically sealed shell H and means for limiting the downward movement of the operating mechanism in the event that abnormal jars are imparted to the unit. This resilient mounting means is intended to sustain the compressor yieldingly in various positions which it may assume during a shipping operation. Even if the entire unit is tipped sideways during shipment, at times, the spring suspension is intended to maintain the motor compressor unit fairly stable during the shipment. The spring suspension together with the movement limiting means is intended to prevent any part of the motor compressor unit itself from engaging any part of the casing during the shipping operation. To this end brackets are provided inside the shell as shown at ill. I provide preferably three brackets similar to the bracket shown at 10 in the single cylinder type of compressor of the embodimerit shown in the drawings hereof. Each bracket it is welded to the side wall 2 of the lower portion L of the shell and each is constructed to provide a horizontal spring seat H. Each seat l l is provided with an upper bend bulge 12 which extends into a corresponding bulge i3 formed in a spring retainer i l. The spring retainers M are cup-shaped except for an. outwardly extending projection or ear 15 formed on each. The cylindrical portion of each retainer is upward inserted within the lower coils of its associated coil spring 5. The ear I5 of each spring retainer is inserted between the lower coil and the next coil of the associated spring and thus is secured to the associated spring 16.

The motor unit M is provided with a cylindrical frame I? formed as a part of a unitary casting It. This frame H is formed with three outwardly extending lugs, one of which is shown at It. Lugs 19 are drilled as at 20, each to receive the upper portion of a rod 21. Each rod 2! has welded thereto a spring retainer 22 which is similar in all respects to spring retainers (-4 but is turned over relative thereto so that the cylindrical portion extends downward within the upper coils of the spring [6. Each retainer 22 is provided with an ear or projection 23 which extends under the upper coil of the spring and over the second coil thereof to secure the spring retainer to the spring. The rods H are threaded at their upper ends and are clamped to the lugs 19 by nuts such as the nut 24, the retainers 22 being drawn tightly thereby against the lower parts of the lugs 19. The springs 15 are thus interposed between the bottom of the lugs l9 and the seat I l and surround the cylindrical portions of the retainers l4 and 22. Ears I5 and 23 project between turns of the coil springs and thereby tie or secure the springs to the retainers Id and 22. The vertical or gravity load of the mechanism is supported by the springs 16. Accordingly, it will be observed that the operating mechanism is yieldably mounted so that it may move or vibrate relative to the shell both in a relatively upward direction and a relatively downward direction. The springs in compression tend to sustain the mechanism against its tendency to move downward in the shell and in case the shell is reversed, the springs in tension tend to sustain the mechanism from movement in the opposite direction. The springs are under suitable compression or tension and thus in torsion tend resiliently to sustain the mechanism against lateral movement within the shell.

As will benoted by reference to Fig. 4, the supports or brackets in are symmetrically arranged. Howeventhe supports are arranged according to the load to be carried. It will be noted by reference to Fig. 4, that the center of the heavy cylinder portionof the compressor unit C is eccentric of the shaft S and lies substantially equidistant between two supports and opposite to the third support'so that the heavy load is distributed between the three supports.

The electrical mot-or M comprises windings 28 carried-by a stator body 29 which is preferably press fitted into the cylindrical or ring part I! of the main body casting 1-8. The rotor or armature of the motor is shown at 3! mounted upon the vertical shaft S.

The main casting I 8 includes in addition to the upper frame ll, an intermediate spider structure extending downwardly therefrom and below the spider a cylinder and a lower portion 3B.

An upper bearing for the shaft S is shown at 32 which preferably takes the form of a separate piece secured to the spider 34 by a suitable num o'er ofjcap screws as shown at 33. 1

As stated above, I provide a compressor unit C. This is also formed integrally with the main casting It... The spider structure 34 connects with an integralportion forming the cylinder 35 and the lower portion 36. The portion 36 provides a lower bearing 31 for the shaft S. The shaft S has a crank throw 38 and a lower bearing portion 39. The under side of the rotor 31 carries a counter-balancing mass 40 for the throw 38, and a counter-balance weight 4| may be disposed on the top of the rotor opposite the counter-balance weight 4i). Disposed within the cylinder 35 is a piston '42 driven by a connecting rod 43 through a wrist pin 44 At its opposite end the connecting rod is driven by the crank throw 38. A spring clip if: has one end 48 which extends through a notch in the wrist pin and into an opening in the piston. The clip is disposed within the hollow wrist pin and it holds the wrist pin against axial displacement in the piston. The connecting rod has an oil passagewa 41 therein. The cylinder valve plate is illustrated at 48, and it is equipped with a suitable inlet valve t9 and an outlet valve 5 1.

Means are provided for the inlet of the expanded gases into the sealed unit and the withdrawal of the compressed gases therefrom, such gases during their stay within the sealed unit being compressed by the compressor unit C including the pump cylinder35 and the piston 42. The inlet for the expanded gases is shown in Figures e and 5. The inlet pipe 25 is connected to the inlet 25a, which extends through the wall of the shell and then projects upwardly to above the levelof the lubricating oil in the shell, the level of the lubricating oil being indicated at 26. Surrounding the upper end of the inlet pipe 25 is a screen structure 21. The expanded gases thus fill the shell above the level of the lubricating oil therein. They are then'dr'awnthrough a pipe 52 into cylinder 35 by the suction created therein. One end of this pipe or tube 52 is open as shown at 53 and the opposite end of the pipe fits into a recess 56 in the cylinder head 55. Intermediate its ends, the pipe 52 is wound around the cylindrical frame H. The recess 54 leads to a valve chamber 58 from which the gases pass through the valve 49 to the working chamber 50 cf the cylinder 35. Reciprocation of the piston 42 forces the gases from the working chamber 50 of the cylinder 35 past the valve into the outlet chamber 66. From the outlet chamber 60, the gases pass by an internal passageway (not shown) into the mufller 57 (see Figure 4). From the mufier 51 the gases pass through a tube 58 to the outlet 59.

As has been explained above, the motor compressor unit mounted within the sealed shell is resiliently supported therein. It is desirable, therefore, that the inlet and outlet connections between the compressor unit and the shell shall not interfere with this resilient mounting. I so arrange these connections. Also I provide means whereby there shall be'a heat exchange between the motor unit and expanded refrigerant and whereby there shall be a heat exchange between the lubricating oil and the compressed refrigerant and to a slight degree between the lubricating oil and-the expanded refrigerant. Moreover, I

provide means whereby the expanded gas conduit .or tube which I show herein as the specific means for affecting heat exchange between the expanded refrigerant and the motor shall not be allowed to vibrate independently of the motor unit. The pipe 52 intermediate the endwhich is inserted in the recess 54 and the opposite open end 53 is formed as stated above into one or more convolutions around the ring part ll of the frame or body member it. The convolutions are clamped tightly to the body by clamps 6! and thus the tube is prevented from vibrating independently of the motor unit. The convolution or convolu tions of the tube or pipe 52 function as a muffler and also absorb heat from the ring member H which forms a portion of the motor unit M. The clamps 6% are L-shaped in cross section having a horizontal leaf E2 and a vertical leaf 63. The

horizontal leaf is perforated to receive the associated rod 2! and isclamped between the nut 24 and the top side of lug i9. Tapered-slots 64 formed in each of the vertical leavesGS fit over a portion of the coiled tube 52 and force the tube into contact with the ring portion if of; the casting it which forms a frame for the motor M.

The tube 58 leading from the muiller 57 as shown in Figure 4 is turned up at 53c; hasa horizontal section as shown at 58b which passes .through one of the slots 84;;thenturns down at 58c; and is formed with one or more convolutions 58d. intermediate its connection with the muffler and its connection with the outlet 59.

As also shown. in Figure 3, the convolutions'158d of the pipe or tube 58 are positioned in the lower. part of the casing or. shell within the lubricant containportion of the shell. Inasmuch as the inlet refrigerating gas flows freely-in the casing H, there is no mechanical connection requiredbetween the inlet and the compressor. Due to the outlet connection through the convolutions of the tube 58, the operating mechanism comprising the motor and-compressoryetc. may vibrate relative to the shell on its spring mounting inasmuch as the coil of the tube '58 which constitutes the only other mechanical connectionbetween the. operating mechanism and theshell'yieldingly accommodates and helps in resiliently absorbing the relative movement.

As suggested above, I provide means for limiting relative movement of the motor compressor unit with respect to the shell. Referring to Figure 3, it will be noted that should the motor compressor unit move downward therein the rod 21 will strike at its lower end against thebulge- 13 on the spring retainer l4 and thus limit downward movement of the unit. Also it will be noted that upward movement of the unit will cause the upper portion of the clamp 6! to contact with the portion 65-of the wall 4 of the upper section U directly abovethe clamp as shown. Shouldthe "shipment or other careless handling of the assembly.

I provide means for lubricating the various bearings of the motor compressor assembly lneluding a lubricating pump driven by the operating shaft S. The lubricating system is of the pressure type in that lubricating oil, Which is contained in the bottom of the shell, as shown in Fig. 3, is positively pumped to the moving parts requiring lubrication. The pump structure is embodied in the shaft and its lower bearing construction so that some of the parts perform dual functions. A thrust plate 5'! is secured to the bottom of the body casting I8 by cap screws 68 and the shaft S rests upon this thrust plate. The thrust plate 61 has an aperture 69 therein which is an inlet aperture for the pump and this may be, and preferably is, covered by ascreen H which filters out any large particles of extraneous material. Between the thrust plate 61 and the bearing 31 is another plate 12 which has an aperture 13 (see Fig. 6) formed therein that fits around the lower end of the shaft but is larger than the shaft and eccentric thereto. The shaft is provided with a cross slot in which is located a vane or blade 14, the length of which substantially equals the diameter across the opening f3 and the edges of which are fashionedso-as to wipe the inner walls of the aperture l3 as the shaft S rotates. The shaft and the aperture is form a crescent shaped pump chamber i5. Positioned substantially at'the opposite end of the pump chamber from the aperture 69 is a passage or notch 16 in the lower bearing 3'! and this constitutes an outlet for the pump. a

The operation of the pump will be appreciated reference to Fig. 6 where the shaft is arranged to rotate counter-clockwise as shown by the arrow. As the shaft rotates, the vane 74 reciprocates back and. forth relative to the shaft and its ends, accordingly, constantly wipeor substantially wipe the'walls of the crescent shaped opening 75. As one end of the vane. moves through the crescent-shaped opening 15 from the inlet 59 to the outlet-T6 it pushes the oil in front of it through the outlet 76 andcreates a partial vacuum back. of the vane and the pressure in the casing forces the oil through the'inlet fitso as to--fi1l the crescent shaped chamber or portion thereof to the rear of thevane, In other words,

it might be said that movement of the vane sucks opening 75. It will benoted that both ends of the vane function in the same manner and that there are two pumping impulses for each rotation of the shaft S. H

The shaft is provided with a circumferential groove H which communicates with the opening or passage 15 and it also has a diagonal groove i3 on its surface which communicates with the groove ii. Accordingly, the pumped oil fills groove ii and flows through the diagonal groove it. In this way, the oil reaches and lubricates the bearing surfaces of the bearing 37 at the lower end of the shaft 5.

The shaft has an axial passage l9 and a lateral port 8! which connects the lower end of the passage '19 with the groove ll. Accordingly, the pumped oil moves through the port 8| and up through passage 79. Another port 82 in the shaft connects the upper portion of passage 79 to a helical groove 83 so that the pumped oil flows through port 82 and through groove 83 to lubricate the upper bearing 32-. r

I provide means to cool the oil by contact with the inside of the casing 1-1. This also insures that while oil is supplied to lubricate the upper bearing 32, excess oil is not forced out by too great pressure to enter the space between the rotor 3i and the stator 2%. Attached to the top of the shaft S and registering with the axial passage 15 is an open ended tube 8% having its upper end i.

horizontal bearing surface for the lower side of the connecting rod 33 at the throw 33 and thus maintains the horizontal position of the connecting rod.

The electrical control is illustrated in Fig. 3,

4 and 8. A combination of an overload thermostat and a starting relay is mounted compactly in a box or casing 8'! which is secured to the shell. This box covers three conductor plugs 88, S8 and 9i hermetically mounted in the wall of the shell. which is arranged to break the motor circuit under certain conditions in order to protect the driving motor.

The main electrical conduit 93 may enter the box and from it one wire 94 may extend to the thermostat $32 and a wire 85 extend from the thermostat to the terminal plug 9!. Two wires 97 from the conduit 93 connect with the plugs 88 and 53. The windings of the motor and the relay (not shown in detail) are arranged so that when the motor is starting, current is conducted the motor through all three plugs 38, and 8d. The current through plug 89 runs to starting winding. However, after the motor s started the relay functions to open the connowion to the plug 89 and thereafter the motor runs on the running circuit through the terminal plugs 58 and 9f. This arrangement of the motor and a starting relay is not, in itself, new and needs no detailed disclosure. 1

I provide means to open the motor circuit whenever excessive temperature is developed. The thermostat 92 is located in one conductor of the main lead. This thermostat 52 is positioned against or substantially against the exterior wall shell itself.

Within this box is the thermostat :52, k

of the shell. The thermostat is arranged to open the circuit on either of two conditions. If the current is too heavy the thermostat control 92 is arranged to break the circuit and thus protect the motor. If the motor and the compressor develop an unduly high temperature, which may be due merely to the heat generated by the mechanical operation of the machinery, this heat is transmitted to the thermostat and it will open the circuit to protect the motor and other mechanism. The thermostat, itself, maybe of any known construction and needs no detailed disclosure. One point of novelty is believed to be the mounting and assembling of the thermostat upon the sealed Thus. the entire refrigerating unit including the interior compressor mechanism, its shell, and electrical control features constitute a complete, single unit construction.

In general operation of the unit disclosed in this application, expanded refrigerant gases are drawn in through the inlet 25. Passing upward through a tube 25a to the top of the tube, they escape into the interior of the casing through the Screen structure 2'1. Operation of the pump or compressor C sucks these expanded gases in through the open end 53 of the pipe 52 and into the valve chamber 56. Thence they pass through the valve 49 into the operating chamber 50 of the compressor 35 and then out past the valve 51 into the outlet chamber EB. Thence they pass into the mufiler 51 and through the outlet tube 58 and the outlet 59. From the outlet 59, the outgoing gases flow through a condenser (not shown) where the gases are liquefied and then in a controlled manner are conducted to an evaporator (not shown) Where the liquid refrigerant is vaporized and is utilized to coo-l in the desired manner. Thereafter, the expanded gases are returned again to the compressor through the inlet 25.

The bearings of my improved unit are lubricated by the lubricating pump disclosed in Figure-6, and elsewhere and the ciated with the pun p. The resilient mounting of the motor compressor unit is accomplished through the springs 16, and coiled outlet tube 58. Heat exchange between the tube 52 and the tube 58 and the motor and the lubricant is accomplished as has been stated.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

I claim:

1. In refrigerating mechanism, a sealed shell having a gaseous refrigerant inlet emptying therein; a motor-compressor unit within the shell, said motor having a stator, said compressor having a gaseous inlet and having an outlet; a tube wound around the stator and havin an open end for receiving gaseous refrigerant from the interior of the shell, the other end of the tube being connected with the inlet of the compressor, said tube being arranged in intimate and direct contact with the periphery of the stator and also functioning as a mufiler; and a fluid connection from the outlet of the compressor extending through said shell.

, 2. In refrigerating mechanism, a sealed shell having a gaseous refrigerant inlet emptying therein; a motor-compressor unit within the shell, said motor having a-stator, said compressor having a gaseous inlet and having an outlet; a tube wound around the stator and having an open end for receiving gaseous refrigerant from 9 the interior of the shell, the other end of the tube being connected with the inlet of the compressor, said tube functioning as a mufiler; means for clamping the tube in intimate and direct con tact with the periphery of the stator; and a fiuid connection from the outlet of the compressor extending through said shell.

3. In refrigerating mechanism, an assembly comprising, in combination, a sealed shell having an inlet and an outlet; a motor-compressor unit within the shell, said motor including a rotor and a stator; means for resiliently supporting the assembly in the shell spaced from the walls of the shell; a tube wound around the stator and having one end connected with the inlet and the other end connected with the compressor; and clamping means for holding the tube in position against the stator, and providin a bumper between the unit and the shell for preventing the stator from striking the shell in the event of abnormal jars to the assembly.

4. In refrigerating mechanism, an assembly comprising, in combination, a sealed shell having an inlet and an outlet; a motor-compressor unit Within the shell, said motor including a rotor and a stator; means for resiliently supporting the assembly in the shell spaced from the walls of the shell; a tube wound around the stator and having one end connected with the inlet and the other end connected with the compres- 10 shoulder portion extending above the clamping means, said clamping means being arranged to strike the shoulder and limit the movement of the assembly in the event of abnormal jars to the assembly.

WILLIAM W. HIGHAM.

REFERENCES CITED The following references are of record in the file of this patent:

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